This article addresses potential methodological and terminological
limitations of Functional Assessment, and proposes an approach we are
developing to address these concerns. The authors propose that current
methods of assessment and data analysis may yield a specific behavior
pattern due to the effects of reinforcement that could occur during the
analog conditions themselves. Shaping of identified target behaviors
during analog conditions is one possible problem discussed that may
result in masking or obfuscation of the "true function." A
methodology being developed by the authors to minimize this and other
potential problems that incorporates a means of quickly determining
effective treatment is presented and discussed.

Functional assessment is a hallmark of current behavior analytic practice, appearing in over 100 articles in the Journal of Applied
Behavior Analysis since 1981. Treatments derived from functional
assessment methodology assist in the reduction of disruptive classroom
behavior (Horner & Dodson, 1993), severe self-injurious behavior
(Vollmer & Vorndran, 1998), the ingestion of inedible substances
(Mace & Knight. 1986), and reducing stereotypy (Kennedy, Meyer,
Knowles, & Shukla, 2000). There has been a great breadth and scope
of work done in this area over the past two decades with significant
progress in the development of the methodology. Functional Assessment
has become such an integral aspect of the field of Applied Behavior
Analysis that it is now a requirement by the federal government for use
in educational programs nationally for exceptional children under IDEA
'97. In this article, we are addressing a specific methodological
limitation we have seen which may be resolved in part via the use of a
molecular analysis approach that we have been developing.

Terminological and Methodological Issues in Functional Assessment

We will address both the terminological and methodological issues
in functional assessment, and then present suggestions to address the
concerns raised. First, we shall focus on the terminological issues, and
second, methodological issues in functional assessment.

Use of the term "Function"

Heretofore, the term "function" in the research
literature (Iwata, Dorsey, Slifer, Bauman, & Richman, 1994, Mace,
1994, O'Neill, Horner, Albin, Storey, & Sprague, 1997, Vollmer
& Smith, 1996) which has been used to refer to maintaining
consequences, may pose complications with respect to use of the term
itself. When referring to function, one is unclear as to the basic
concept involved. Are we merely referring to any reinforcer that can be
readily identified as a maintaining consequence of a particular response
class; or does the term function refer to the initial reinforcer that
shaped the behavior to begin with? The reason we raise this concern is
that we have observed situations in which the "original "
reinforcer appears not to be readily evident, and another more evident
reinforcer that is also maintaining the behavior was identified as the
function. This very problem, which is the primary topic of discussion in
this article, is further complicated by the lack of terms to adequately
illustrate the issue because it has not previously been a focus of
concern by behavior analysts.

As an example, which we will more fully describe below, a 15 year
old student in our school diagnosed with autism, began engaging in
several challenging behaviors including rubbing his ears, loud
vocalizations, leaving class and wandering about the school grounds. The
behavior analyst conducted a functional assessment and initially
determined that the function of the behavior was teacher/staff attention
due to the persistence of the behavior when these personnel approached
him and tried to find out "what was bothering him." As it
turns out, attention was a current reinforcer that served to maintain
these behaviors, however, the "true" or "original"
function was escape from discomfort due to problems related to recent
medical treatment for an ear infection. Once this medical problem was
addressed, the behaviors subsided and were no longer a problem during
school. In this case example, the readily evident reinforcer did serve
to maintain behavior i.e. current function, and eliminating it was
necessary for effective treatment, but it did not reduce the rate of
behavior. Until the "original" function was identified,
appropriate and effective treatment was not possible.

[TABLE 1 OMITTED]

[TABLE 2 OMITTED]

Proposed Terms

First, use of terminology needs to be addressed before we can
meaningfully proceed to addressing the methodological concerns. We
propose utilizing the terms "original function," and
"current function." "Original function" refers to
those reinforcers responsible for the initial shaping and maintenance of
the target behavior. Alternatively, "current function" refers
to those readily evident reinforcers that have come to additionally
maintain the same behavior as that maintained by the original function.
Reinforcers that are identified as part of the "current
function" may have acquired their reinforcing properties at some
point after the original function initially shaped the behavior. One
possibility is that such reinforcers may acquire their status as a
"current function" during an analog condition. That is, it is
possible that a behavior, such as self-injury may have been initially
shaped by escape from task, but attention also served to reinforce it
during an analog condition. This is not to say that there are not a
number of other ways in which a behavior class can come to be controlled
by multiple functions. Referring back to the case study, above, the
following table will clarify the role of the definitions in identifying
the different types or classes of functions.

The situation illustrated in Table 2, item 2, above, teaching
replacement skills for "inappropriate attention seeking" is
not likely to alleviate the problem behavior in question, and may in
fact result in exacerbating the problem.

Summary of Terminological Issues

Since our goal as behavior analysts is to identify the function of
behavior that leads to determination of effective treatment approaches,
identifying the original function becomes crucial. If one cannot
identify the original function of the behavior, then we may not be able
to identify the relevant reinforcers that would be necessary to devise
an appropriate treatment intervention. Some ways in which using only
current function may hinder effective treatment include (a) possibly
teaching the wrong replacement behavior; (b) allowing access to the
wrong reinforcer, (c) eliminating access to the reinforcer of
"choice" (original function) for that individual, and other
errors. Therefore, the terms we propose above with regard to function
will provide a foundation upon which we can meaningfully discuss
functional assessment methodology.

Methodological Considerations

In light of our discussion to this point, we propose that a key
purpose of functional assessment should be to identify and distinguish
between original function and current function. A further elaboration of
the case example used above may help illustrate and clarify this
distinction. The student in our educational program we referred to
earlier, began to engage in an increase in challenging behaviors
including leaving his classroom, roaming the hallways, banging on
objects, loud vocalizations, rubbing his ears, and refusing redirection to his program area and task. A functional assessment was conducted,
which included review of prior records and direct observation. The
behavior analyst observed that these behaviors persisted when staff
approached this student and attempted to redirect him to his classroom,
or attempted to find out what the problem was. His teacher and behavior
analyst concluded that the function of the behavior was attention
seeking. The behavior analyst additionally considered the fact that a
week earlier he had an ear infection that resulted in his pacing
behavior, leaving his assigned classroom, banging on objects, and
rubbing his ears. She was informed that he went to his physician's
office and received appropriate treatment including an ointment to help
reduce the itching and irritation in his ears. As a result of
information confirming appropriate medical treatment, the notion that
the function of the behaviors could actually have been an attempt by
this student to reduce the discomfort in his ears was ruled out in favor
of the attention-seeking hypothesis. However, all attempts to address
this behavior via various means (such as teaching appropriate means of
requesting attention, asking for time with staff at breaks, asking for
help, etc.) were unsuccessful.

After a discussion with the behavior analyst, the function was
re-evaluated, and the medical issue was once again considered. A
check-up with the nurse was rescheduled, and it was determined that
there was a build-up of the ointment in the ears that was potentially
responsible for discomfort. Due to the student's lack of verbal
communication skills, he was unable to indicate this problem to his
teacher (i.e. that the treatment itself was responsible for the current
challenging behavior). His mother and physician were contacted, and
application of the ointment was discontinued, and the ointment in his
ears was cleaned out with a swab. After this, the problem behaviors
ceased and the student was again on-task, and performing as usual at
school.

The lesson we learn from this case example is that our
methodologies may lead us to incorrect conclusions about the
"true" or original function of the behavior we are trying to
treat, and may result in inappropriate or ineffective treatment. The
behavior analyst had to distinguish between current and original
functions to determine the most effective treatment method, which in
this case was a medical solution. It may have been the case that there
was an attention component in that the student's behaviors may have
also been serving a communication function to alleviate his discomfort,
or as a means of coping with the discomfort, both of which are forms of
behavior maintained by negative reinforcement. However, this raises
additional methodological issues. In the next section of this article,
we will identify and discuss several of these issues, and how they may
interfere with determining function.

Reinforcement History as a Relevant Factor

We are proposing that when conducting a functional assessment
(including functional analysis methods), we may need to focus our
efforts on identifying the consequences that have initially resulted in
the shaping and maintenance of the problem or challenging behavior (i.e.
original function). As mentioned earlier in the article, the process of
conducting analog conditions may itself result in new or added
reinforcers maintaining the behavior during an analysis that may or may
not be relevant to the original function of the behavior. Hence, we see
our task in functional assessment ultimately as developing a means of
identifying the reinforcers that were responsible in the past history of
the individual in shaping and maintaining those behaviors that are
identified for treatment (Tatham & Wanchisen 1998; Wanchisen &
Tatham, 1991). To the extent that such a complete analysis is possible,
there may continue to be limitations in the existing methodology, but
through discussion and research, we suggest that further advancements of
this powerful methodology can be realized.

Role of Establishing Operations in Functional Assessment

One must consider the roles of establishing operations in the
functional assessment and in conducting analog conditions in particular.
The reinforcers provided in any given analog condition may serve to
alter the establishing operation (EO, cf. Michael, 1993, Schillinger
& Blakely, 1994), which may have been responsible for occasioning
the emission of the problem behavior being evaluated. We are proposing
an approach that allows for a means of assessing function in which the
effects of altering EOs, as well as other factors such as effects of
particular reinforcement history, can be evaluated on a moment-to-moment
basis. Hence, in some instances we may be looking for reinforcers that
may quickly, albeit temporarily, decrease behavior rates. The behavior
would likely decrease in frequency, or cease due to temporarily altering
(reducing or eliminating) the value of the reinforcer, indicating a
change of EO function. This decrease may only be seen in a molecular
analysis, which also can indicate effective treatment simultaneously,
maximizing the efficiency of the analysis.

Molecular Functional Assessment

We refer to the method we are proposing as a "Molecular
Functional Assessment." In this approach, we do not collapse data
on a large scale and look at summary statistics such as rate measures or
averages. Instead, we assess the momentary (i.e. "molecular")
changes in behavior, typically in 30 second time frames, to be able to
determine effects of environmental factors and reinforcement history as
the behavior changes during the actual assessment. This methodology will
permit for the fine-grained analysis of data necessary to distinguish
current from original function, assist the behavior analyst in
determining effects of prior history of reinforcement, establishing
operations, and aid in determining the other factors such as effects of
Sds on the behavior. In addition, the method includes an evaluation of
effective treatment intervention.

Practical Application of the Methodology: Purpose and Procedures

The Molecular Functional Assessment methodology focuses on
determining original function by systematically identifying and
eliminating any possible current function(s), while also evaluating
effective treatment. We applied the molecular functional assessment
methodology to assess the behaviors of a child referred to our program
who displayed aggressive behaviors and who also had apparent eating
difficulties.

METHOD

Subject

A 10 year old male living in the residential program and attending
our day school, served as the subject of the experiment. This child,
whom we shall refer to as Jimmy, was admitted to the program from home
where his adoptive parents were unable to effectively manage his
behaviors and medical needs. Jimmy's behavioral concerns as
observed in our program consisted of aggression in the form of hitting
others, and frequent requests for food. Jimmy was functioning within the
moderate range of mental retardation, and his vocabulary was very
limited, and included the ability to say "eat." The family and
funder requested that the issue of frequently requesting food be
addressed as a target behavior in addition to aggressive behavior. This
request was based in part on a practical issue, and a health issue due
to reported food allergies for many food categories, and concern about
his being overweight.

Procedure

During the first 5 minutes of the analog conditions, the
experimenter reinforced food mands and ignored aggression. During the
next 5 minutes, the experimenter responded to food mands with a verbal
"no," and aggression resulted in food delivery.

[ILLUSTRATION OMITTED]

Condition 3 was a repeat of Condition 2. The next condition was the
treatment assessment phase. The treatment intervention that was chosen
was based on results of the above conditions, in which we concluded that
the function of the behavior was access to food via aggression. Jimmy
was prompted by the experimenter to engage a task for 30 seconds if he
manded for food, which resulted in delivery of a food reinforcer at the
end of the period if the child was on task. Jimmy was offered a choice
of activities that he typically preferred. This condition was carried
out for 5 minutes. In the final treatment phase, which also was
implemented for 5 minutes, Jimmy received food reinforcement if he
manded, was on task for 30 seconds, and did not display aggression.
There were no prompts to engage in the task, and he was given food
reinforcement after 30 seconds of on-task behavior. Engaging in the task
was Jimmy's choice, and he was offered known preferred tasks based
upon prior observation.

RESULTS

Figure 1, below, shows the data obtained from this functional
analysis. Note that the conditions were run in very short time periods,
and were also conducted in two sessions on two consecutive days, for a
total of 30 minutes for all conditions. Inter-rater agreement for the
two independent observers was at 100% for all conditions. Note that in
condition 1, aggression did not occur when not reinforced, and food
mands rapidly increased during the five-minute phase. In condition 2, we
see a rapid reversal of this trend, in which aggression rates rapidly
increased when reinforced. But the salient feature of this analog
condition is that we see a short-lived extinction burst for food
manding, with a rapid deceleration by the midpoint of that condition,
and then both aggression and manding rates co-vary. This result was
replicated the next day when condition 2 was continued for ten minutes,
in which we see evidence for a behavior chain of food manding, which if
not met, was followed by aggression, which then resulted in food
delivery. Due to the strength of the behavior chain, and its resistance
to extinction, we concluded that this behavior chain was reinforced in
the home setting with food, and was an "original function."
These behaviors were the main reasons for Jimmy being referred to our
program for treatment, which was substantiated as a stable behavior
pattern by our functional assessment method.

[ILLUSTRATION OMITTED]

In the treatment phase that followed the assessment phases (1-3),
the purpose was to reduce rates of aggression as well as food mands, due
to concerns from the family with regard to eating too many snacks.
Recall that in this condition, Jimmy was prompted to engage in a task
for 30 seconds, which resulted in delivery of an edible reinforcer if he
did so without aggression. Mands resulted in a prompt by the
experimenter to engage in the task. Aggression was ignored, and did not
result in food reinforcement. The results of this condition were zero
incidents of aggression, and very low rates of food manding. The final
condition was a straightforward DRA in which 30 seconds of unprompted
on-task behavior was reinforced with food, and both aggression and food
mands were ignored. In this condition, we saw a short extinction burst
for mands, which dropped out by the middle of this short phase, and one
instance of the behavior chain of manding, then aggression, both of
which were ignored. The data support the idea that prompting on-task
behavior contingent on mands appeared to reinforce, and hence, maintain
the food mands, which indicates that the DRA procedure was overall more
effective, which might have been verified by extending that condition.

DISCUSSION

In this study, we evaluated a unique methodology for assessing data
from a functional analysis to determine function. We utilized our
knowledge of histories of reinforcement and conditioning (cf. Tatham
& Wanchisen, 1998; Wanchisen & Tatham, 1991) to devise a
methodology to determine original function. If we determine via multiple
observers that there was not a very rapid deceleration of the rate of
behavior following an extinction burst in the extinction condition, then
we can further con "current function." We have also proposed
that there are two areas of concern 1) methodological issues with regard
to knowing prior reinforcement histories, and masking or obfuscation by
the reinforcing conditions in an analog condition, and 2) terminological
issues that arise with regard to the manner in which to speak of two (or
more) types of potential functions utilizing behavior analytic terms
that are precise and technical, and that addresses different
reinforcement histories. We have proposed some conventions for
terminological usage to refer to two different types of function:
"original function" and "current function." We have
also proposed a modification to the methodology in the form of a
functional assessment approach which can quickly identify changes in EO
effects on reinforcement and which aids in identifying "original
function" by conducting pointed, brief analog conditions,
conducting a molecular analysis of the data during the actual analog
conditions, and then moving on to evaluating effective treatment
interventions. The suggestions we are making are intended to stimulate
further discussion and hopefully research, particularly on the problem
of identifying the effects of prior histories of reinforcement
(Wanchisen & Tatham, 1998). If one can determine a means of
assessing the effects of prior histories of reinforcement, one has a
better opportunity to identify the original function.

To further clarify our approach, we are proposing that
identification of the original function of behavior is crucial to more
effective and efficient treatment, and to do so, one must determine or
eliminate current function. We further propose that behavior maintained
by a current function is weaker than that maintained by the original
function that was responsible for the emergence of the behavior to begin
with. If we eliminate the original function of a target behavior,
current function(s) may continue to maintain it, but the behavior will
be weaker and much less stable. The reason for this is that current
function serves to support behavior, but eliminating the current
function is not sufficient to reduce or eliminate rates of the target
behavior. If we can find the original function, which is primarily
responsible for maintaining the behavior, it will lead to a more
effective and efficient treatment intervention. In application, we would
expect that if we were to eliminate or alter the effects of current
function(s), we may see either a small decrement in rate or frequency of
the behavior, or a transient effect consisting of an extinction burst
with stabilization at or near the previous rate or frequency of
behavior. However, if we eliminate or alter the effects of the original
function, we would be more likely to dramatically reduce or eliminate
the rate or frequency of behavior very rapidly.

In our case example discussed earlier, the approach assists in
confirming the identification of the original function while also
evaluating treatment effectiveness to distinguish between current
function, teacher attention, and original function, discomfort created
by the ointment in the student's ears. Consequently, we can see
that eliminating teacher attention may serve to weaken or reduce rates
of behavior to some extent. However, because we have not identified the
original function (ointment in the ears resulting in discomfort) we will
not be able to finish our task of completely eliminating the target
behavior, and we will not be efficient in determining the appropriate
replacement behavior or effective treatment intervention.

Benefits of a Molecular Approach to Functional Assessment

The molecular functional assessment approach may have several
benefits that address these concerns, since it looks at the behavior
relative to function in very short periods of time. These benefits will
be listed and discussed below.

1) As suggested by the name we chose, the molecular approach
assesses function on a moment-to-moment basis (in this study, we look at
the progression of behavior in 30-second segments within a given analog
condition). Standard methods tend to look at more molar measures such as
rates or averages which can make it difficult to evaluate effects of
extinction or determine whether a shaping process is occurring. Such
analyses are crucial to distinguishing current vs. original function.

2) Each of the analog conditions are alternated with strategic
environmental manipulations to determine the original function. The
molecular approach will minimize the problem of establishing a new
(current) function, and help assess the existence of a current function.
By evaluating data on a moment-to-moment basis, the behavior analyst is
better able to distinguish patterns suggesting that the behavior being
evaluated is resistant to extinction or extinguishes rapidly. When a
reinforcer is presented contingently in the initial analog condition
that is presumed to be function of the behavior, and in subsequently is
withdrawn, a molecular analysis of the data will reveal one of two
primary patterns. First, resistance to extinction with an extinction
burst would suggest that the behavior was more likely to have been in
the person's existing behavioral repertoire (original function).
However, if the behavior extinguishes rapidly in this subsequent
condition, the conclusion may be made that behavior that was maintained
by the reinforcer in the prior analog condition was weak, was more
recently shaped, and firm that this behavior was in the existing
repertoire of the person (i.e. the result of prior conditioning and
maintenance over some time period). Furthermore, we also have a firm
basis for arguing that our current analog condition did not result in
establishing a new (i.e. current) function. After this demonstration, we
also immediately implemented a treatment intervention designed to teach
a functionally equivalent replacement behavior, and evaluate its
efficacy.

Our conceptualization is that utilizing prior reinforcement
history, knowledge about rates of behavior, and response strength, along
with a moment-to-moment analysis of behavior, allows for a means to
quickly determine function. The argument is that we can determine
original function via rapidly changing conditions utilizing the
alternating treatments (or multi-element baseline) design (Barlow &
Hayes, 1979, Hersen & Barlow, 1978, Ulman & Sulzer-Azaroff;
1975). One indicator of original function is the absence of an
acquisition curve. That is, the behavior in question rapidly emerges,
and additionally, we see an extinction burst during the extinction
session. The empirical data presented here are a demonstration of the
utility of our molecular approach to functional assessment, and further
demonstrates that it is possible to determine original function
directly. In this case, the original function appeared to be the only
function in place. Our approach offers a means of minimizing
establishment of a current function during the analog conditions;
identifying current functions if they exist; and then distinguishing
between original and current function as warranted. We are proposing
that we have a methodology that can address the issue of uncovering
original function when other possible maintaining reinforcers are
masking that original function. Magee and Ellis (2000) used a similar
approach to eliminate behaviors that occurred in a response hierarchy in
which different behaviors were maintained by the same reinforcer. Our
approach is similar to that used by Magee and Ellis (2000), however, in
our methodology, we identified different reinforcers that were
maintaining the same behavior. Due to the promising results we obtained
with regard to rapidly determining original function, we see the
potential for further research that would replicate and expand upon this
method. We have demonstrated the utility of our approach in a relatively
straightforward analysis that can be applied to more complex situations
such as those discussed in the case example earlier in the article.

Toward a Molecular Approach to Functional Assessment

We have discussed potential difficulties in identifying what we are
referring to as "original function" vs. "current
function." We have also proposed that there are two areas of
concern 1) methodological issues with regard to knowing prior
reinforcement histories, and masking or obfuscation by the reinforcing
conditions in an analog condition, and 2) terminological issues that
arise with regard to the manner in which to speak of two (or more) types
of potential functions utilizing behavior analytic terms that are
precise and technical, and that addresses different reinforcement
histories. We have proposed some conventions for terminological usage to
refer to two different types of function: "original function"
and "current function." We have also proposed a modification
to the methodology in the form of a functional assessment approach which
can quickly identify changes in EO effects on reinforcement and which
aids in identifying "original function" by conducting pointed,
brief analog conditions, conducting a molecular analysis of the data
during the actual analog conditions, and then moving on to evaluating
effective treatment interventions. The suggestions we are making are
intended to stimulate further discussion and hopefully research,
particularly on the problem of identifying the effects of prior
histories of reinforcement (Wanchisen & Tatham, 1998). If one can
determine a means of assessing the effects of prior histories of
reinforcement, one has a better opportunity to identify the original
function.

To further clarify our approach, we are proposing that
identification of the original function of behavior is crucial to more
effective and efficient treatment, and to do so, one must determine or
eliminate current function. We further propose that behavior maintained
by a current function is weaker than that maintained by the original
function that was responsible for the emergence of the behavior to begin
with. If we eliminate the original function of a target behavior,
current function(s) may continue to maintain it, but the behavior will
be weaker and much less stable. The reason for this is that current
function serves to support behavior, but eliminating the current
function is not sufficient to reduce or eliminate rates of the target
behavior. If we can find the original function, which is primarily
responsible for maintaining the behavior, it will lead to a more
effective and efficient treatment intervention. In application, we would
expect that if we were to eliminate or alter the effects of current
function(s), we may see either a small decrement in rate or frequency of
the behavior, or a transient effect consisting of an extinction burst
with stabilization at or near the previous rate or frequency of
behavior. However, if we eliminate or alter the effects of the original
function, we would be more likely to dramatically reduce or eliminate
the rate or frequency of behavior very rapidly.

In our case example discussed earlier, the approach assists in
confirming the identification of the original function while also
evaluating treatment effectiveness to distinguish between current
function, teacher attention, and original function, discomfort created
by the ointment in the student's ears. Consequently, we can see
that eliminating teacher attention may serve to weaken or reduce rates
of behavior to some extent. However, because we have not identified the
original function (ointment in the ears resulting in discomfort) we will
not be able to finish our task of completely eliminating the target
behavior, and we will not be efficient in determining the appropriate
replacement behavior or effective treatment intervention.

Benefits of a Molecular Approach to Functional Assessment

The molecular functional assessment approach may have several
benefits that address these concerns, since it looks at the behavior
relative to function in very short periods of time. These benefits will
be listed and discussed below.

1) As suggested by the name we chose, the molecular approach
assesses function on a moment-to-moment basis (in this study, we look at
the progression of behavior in 30-second segments within a given analog
condition). Standard methods tend to look at more molar measures such as
rates or averages which can make it difficult to evaluate effects of
extinction or determine whether a shaping process is occurring. Such
analyses are crucial to distinguishing current vs. original function.

2) Each of the analog conditions are alternated with strategic
environmental manipulations to determine the original function. The
molecular approach will minimize the problem of establishing a new
(current) function, and help assess the existence of a current function.
By evaluating data on a moment-to-moment basis, the behavior analyst is
better able to distinguish patterns suggesting that the behavior being
evaluated is resistant to extinction or extinguishes rapidly. When a
reinforcer is presented contingently in the initial analog condition
that is presumed to be function of the behavior, and in subsequently is
withdrawn, a molecular analysis of the data will reveal one of two
primary patterns. First, resistance to extinction with an extinction
burst would suggest that the behavior was more likely to have been in
the person's existing behavioral repertoire (original function).
However, if the behavior extinguishes rapidly in this subsequent
condition, the conclusion may be made that behavior that was maintained
by the reinforcer in the prior analog condition was weak, was more
recently shaped, and that one has determined a current function.

4) Another potential benefit of our approach is that one may more
readily observe effects of altering EOs via providing the reinforcer of
which the behavior is a function (i.e. original function). Frequently,
continued presentation of the reinforcer initially responsible for the
behavior (original function) will both strengthen the future probability
of the behavior on which it is contingent, and may also temporarily
result in immediate cessation of the behavior due to the altering effect
of the EO for the behavior. However, the behavior being evaluated may
not re-occur again during a brief functional analysis period due to
absence or alteration of the EO for that behavior. Our approach may
offer a solution to this problem by evaluating rapid changes in behavior
during the course of the analysis at a molecular level (i.e. moment to
moment, or minute to minute). For instance, if a reinforcer is provided
contingently, and we see the behavior occur initially and then cease,
one may conclude that the EO has been altered, i.e. value of the related
reinforcer has been altered (reduced in this example). 4) An additional
benefit of our approach is that it offers an evaluation of effective
treatment intervention, which further supports the conclusion regarding
the hypothesis statement for challenging behavior(s) being evaluated.
This is accomplished by first determining original function, then
proceeding within the same session to another condition in which
replacement behaviors linked to the presumed original function are
implemented in another analog condition. For example, in our experiment,
Jimmy was already able to mand verbally for food by saying
"eat" and had another functional skill of participating in
table-top tasks independently, such as completing puzzles. The
experimenters provided him with a positive activity, which he readily
engaged in, and appeared to have reinforcing properties as a means of
teaching him to wait short periods to gain access to food items. Hence,
we were able to implement an ecological manipulation without requiring
teaching any additional functionally equivalent replacement behaviors to
both eliminate aggressive behavior and reduce the frequency of manding
for food. The rapid reduction in rates of the challenging behavior under
study as demonstrated in the molecular analysis further supported our
hypothesis regarding the original function of the behavior and also
revealed an effective, non-restrictive treatment intervention for Jimmy.

Conclusion

In this paper, we have presented a novel conceptualization of
functional assessment in which we propose that potential functions that
have been identified may not be the reinforcer responsible for the
original shaping of the behavior being targeted for assessment and
treatment. We present a theoretical position as to how the behavior may
come to be maintained in part by other reinforcers that entered into the
situation at a later time, including during functional analysis
conditions. We present a unique methodological approach to resolving
this potential problem, and data from a study we conducted utilizing our
molecular functional analysis approach. In this approach we distinguish
original function from current function based upon knowledge from the
literature about prior history of reinforcement and maintenance of
behavior (Tatham & Wanchisen, 1998), and the analog conditions that
we conducted. We propose that it becomes crucial to identify the
original function of the behavior for treatment to be effective and
complete. If one does not identify the original function, there is a
real risk of teaching what merely appears to be a functionally
equivalent replacement skill, or implementing an inappropriate
intervention (e.g. medical, ecological change). However, when the EO
that evoked the behavior that was part of the original function
re-occurs, then the behavior will re-occur. As a result, our data may
lead us to erroneous conclusions regarding function and the appropriate
treatment intervention. When our treatment fails, then we need to
conduct further assessments to determine why our intervention was not
effective. This state of affairs would be compromising from an ethical
perspective and a financial or managed care environment in which
clinical services and treatment need to be efficient and effective. Our
preliminary research offers promise for this approach to determining
function, and may lead to further developments as additional studies
utilizing the method are conducted and yield data bearing upon our
discussion of functional assessment methodology.

REFERENCES

Barlow, D.H., & Hayes , S.C. (1979). Alternating Treatments
design: One strategy for comparing the effects of two treatments in a
single behavior. Journal of Applied Behavior Analysis, 12, 199-210.